Thread cutter mechanism for loom



Aug. 28, 1956 1. w. KovALEsKl 2,760,52 7

THREAD CUTTER MECHANISM FOR LOOM Filed May 17, 1955 lill TJH |IIN INVENTOR JOHN W. KOVALESKI I ATTORNEY TILREAD CUTTER MECHANTSM FOR LOOM John W. Kovaleski, Worcester, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application May 17, 1955, Serial No. 508,869

11 Claims. (Cl. 139-267) This invention relates to improvements in thread cutting mechanism for looms and it is the general object of the invention to provide a mechanism made in such manner as to operate satisfactorily without requiring very close adjustment of the opening and closing means for the cutting and clamping blades of the mechanism.

In a weft replenishing bobbin changing loom there are usually two threads remaining in the loom incident to each bobbin changing operation, one of these threads being attached to the outgoing bobbin and the other to the incoming bobbin. The present invention is concerned more particularly with the first of these threads, that is, the thread which extends from the selvage into the shuttle box along the front wall of the shuttle and then through the delivery eye of the shuttle back to the dcpletecl bobbin. When the latter is expelled from the loom it does not always remove its thread and the latter may remain in the shuttle box and be swept into the warp shed on the next ight of the shuttle to produce a defect in the fabric.

it has been proposed heretofore to provide a thread cutter and clamping mechanism adjacent to the delivery eye of the shuttle so that only a short length of thread need be withdrawn by the outgoing bobbin. The remaining part of the thread is generally clamped to prevent it from being drawn into the warp shed and at some later beat of the loom this thread is cut at the selvage while still held by the thread clamp. On a later replenishing operation when the thread cutter and clamp open the thread is dropped along a path which is forward of the lay so that there is little danger that the thread will be drawn into the warp shed.

One such mechanism employs a rocking member which opens the thread cutter as the latter moves rearwardly preparatory to a bobbin changing operation. As the lay advances it strikes a part of the cutter mechanism to close the cutting and clamping blades and as the cutter mechanism moves forwardly it engages the rocking member which is free to turn about its pivot without reopening the cutter. It has been found in practice that a cutter mechanism so made requires very delicate adjustment, particularly the setting of the rocking member due to the manner in which the latter is mounted and the stops between which it is permitted to swing. It is an important object of the present invention to provide a thread cutter mechanism having a rod or member mounted for sliding movement and normally held in rear position across the path of a part of the cutter mechanism to open the latter as the mechanism moves rearwardly. When the cutter is closed to cut the thread the aforesaid part returns to its normal position and when moving lforwardly it engages the sliding member and presses the latter forwardly along a path which diverges from the path of the cutter to cause separation of the part and member without opening the cutter.

It is a further object of the invention to relate the two cooperating parts which effect opening of the cutter and clamp mechanism in such manner as to reduce wear Patented Aug'. 28, 1956 on one of these parts. This result is attained by mounting this part so that it can be rotated on its longitudinal axis without changing its operative relation with respect to .the cooperating part which is on the cutter and clamp mechanism.

It is customary to make cutters of the general type to which this invention relates with an oblique guide for the cutting and clamping mechanism which causes the mechanism when returning to its forward normal position to move slightly in a direction toward the center of the loom, the purpose of this motion being to prevent the clamped thread which is still attached to the selvage from pulling out of the clamping part of the mechanism. It is a further object of the invention to utilize the inclined path which the cutter mechanism traverses in combination with an opening means for the cutter movable along a path oblique with respect to the path of the cutter and clamping mechanism While the two cooperative parts are in engagement with each other. This results in a relatively lateral motion on the part of the cutter and clamping mechanism with respect to the opening member which automatically tends to rotate the latter so that it can present new wear surfaces while still remaining in correct position as successive operations of the cutter and clamp mechanism occur.

In order that the invention may be clearly understood reference is made to the accompanying drawings which illustrate by way of example the embodiment of the invention and in which:

Fig. 1 is a front elevation of part of a weft replenishing loom having the thread cutter and clamping mechanism forming the subject matter of this invention applied thereto,

Fig. 2 is an enlarged plan View looking in the direction of arrow 2, Fig. 1, showing the thread cutter in its normal closed forward position,

Figs. 3, 4, 5 and 6 are slightly enlarged vertical sections on lines 3 3, 4 4, 5 5 and 6 6 respectively of Fig. 2, and

Figs. 7, 8 and 9 are diagrammatic views showing the parts of the cutter mechanism in different positions.

Referring particularly to Figs. 1 and 2, the loom frame 1 which supports a weft replenishing mechanism M is in the form of a bobbin changer more particularly for multi-color looms. This mechanism includes a stud 2 on which is rockably mounted a transfer arm 3 having depending arms 4 to which is pivoted a transfer latch 5 normally down but liftable by a rod 6 for engagement with a bunter 7 on l-ay 8 for the purpose of moving the transfer arm to insert a fresh bobbin into the shuttle S. The lay is provided with a shuttle box 10 under the magazine M, this box having a back binderv 11 and having a box front 12 stationary with respect to the lay. The box front is provided with an opening 13 to be in register with a hole 14 in the front wall 15 of the shuttle when the latter is in the box 10. The opening 14 as shown in Fig. 2 is to the left of the delivery eye E of the shuttle. When the shuttle is as shown in Fig. 2 the weft thread W extends from the bobbin B through the delivery eye E across the hole or opening 14 and along the front wall 15 of the shuttle to the left of the adjacent selvage (not shown).

Mechanism not shown herein but well understood is provided to set the magazine for a weft replenishing operation When the weft of the bobbin B is substantially exhausted.

Secured to one of the arms 4 of the transfer yarm is Aan operator 16 which is behind the left hand arm 17 of a lever 18 pivoted at 19 on a fixed part 20 supported from the loom frame as shown in Fig. 1. The lever 18 has a right-hand arm 21 formed with a depending lug 22 through which extends a screw 23 having la head 24 on thel frontend thereof in front of the lug 22. The screw extends rearwardly through an opstanding lug 25 on an arm 26 also pivoted at 19 and a compression spring 27 between the lugs 22 and 25 tends to hold; the lever 18 and. the arm 26 in the normal relative position shown in Fig. 2. Nuts 28 on the rear end of screw 23 behind lug 25 limit the movement of arm 26 from Iarm 21. A tension spring 29 extending between a clip 30 secured to the support 20 and a spring holder 31 between the nuts 28, see Fig. 4, tends normally to hold the lever 18 and arm 26 in the position shown in Fig. 2 with the arm 17 against the operator 16 and a bearing 32 at the right end of the arm 26 in forward position.

A guide holder 35 is secured at 36 to the support 20 and extends to the right to support -a guide rail 37 held to the holder 35 at 3S. A cutter and clamp mechanism designated generally at C is slidable backwardly and forwardly along the rail 37, a carriage 39 for the mechanism C being slidable on the rail and supporting a pivot screw 4i) on which the various operating parts of the mechanism C are mounted. These parts are a leaf spring 41, a fixed cutter blade 42, a moving cutter blade 43, a moving thread clamp member 44, and a fixed clamp member 45. A second leaf spring 46 bowed as suggested in Fig. 2 is at the left of the fixed clamp 45 as shown in that figure and a nut 47 on the screw 40' holds spring 46 against the fixed clamp and also serves to hold the several parts of the cutter and clamp mechanism C in close relation.

A pin 4S xed to the carriage 39 extends through the forward parts of certain of the blades of the mechanism C and has holding relation with other parts. Thus, as shown in Fig. 7 the pin lits into a notch 49 at the forward or right-hand end of the xed clamp 45 and has a similar relation with respect to the fixed cutter blade 42 and the leaf spring 41. The pin 48 passes through ay hole Si) in the movable blade 43 to permit rocking of the latter around the screw 40, and has a similar relation with the moving clamp 44.

Depending from the movable cutter blade is a lug 51 for cooperation with a closing means 52 secured to and extending forwardly from the lay. A forward extension S3 of the movable cutter blade is provided with a lateraliy extending stud 54 which is one of the parts which cooperate to effect opening of the cutter as will be described hereinafter.

in the operation of the matter thus far describedv the parts will normally be in position shown in Fig. 2 with the cutter and lclamp mechanism C held in forward position by spring 29 and with the cutter and clamp blades` of the mechanism C in closed position with the stud 54 in its uppermost position as shown for instance in Fig. 3. When a weft replenishing operation occurs the rocking of the transfer arm effects forward movement of the f operator 16 which rocks the lever 18 and the latter acting through the spring 27 rocks the arm 26 in a counterclockwise direction, Fig. 2, to move the carriageV 39 rearwardly along the obliquely disposed rail 37. This latter motion is caused by a stud 55 mounted forangular motion on the bearing 32 and havinga pin 56V rigid with the carriage 39 passing through the lower forked endv thereof as shown in Fig. 5. The resulting rearward motion Of the mechanism C occurs while the lay is still behind its front center position and as the lay advances toward its front center position the closing means 52 will engage the lug 51 to return the cutter and clamp mechanism C to closed position 'as will be more fully described hereinafter. The mechanism thus far described is somewhat similar to cutter and clamping mechanisms heretofore used, but the oblique disposition of the rail 37 has-a relation to one feature to be pointed out.

In carrying the present invention into effect-there is provided a second or another part for opening the cutter mechanism C as it moves rearwardly. This other part includes a small stand 59 secured by screw 60 to the guide holder 35 as shown in Fig. 3. The upper part of the stand 59 has front and hack guide bearings 61 and 62 respectively in which is slidably mounted a rod or member 63 a part of which is surrounded by a spring or resilient means 64 between the bearings 61 and 62 and exerting a rearward force, to the left in Fig. 3, against a pin 65 passing through the rod 63. The right-hand, or forward, end of the rod 63 is provided with screw threads 66 to receive nuts 67 for the purpose of adjusting the longitudinal position of the rod 63 with respect to the stand 59. The rod 63 is thus slidable along a xed straight line path which diverges from the path followed by cutter and clamp mechanism C as it moves back and forth with respect to the lay. As shown in Fig. 3 the rod 63 is inclined rearwardly and downwardly, but the rod 63 need not necessarily be so disposed` Normally the low rear end of rod 63 occupies a position in the path traversed by the stud 54 as the mechanism C moves rearwardly.

When the mechanism C begins to move to the rear las already described it is closed as suggested in Fig. 3, but as the carriage 39 slides along the rail 37 toward the lay the stud 54 engages the underside of the rod 63 and the latter causes relative downward movement of the stud 54 to open the cutter mechanism C to the position shown in Fig. 7. The carriage 39 will ordinarily have a further movement toward the lay to enable the thread W to enter between the opened blades, after which the closing means 52 will engage the lug 51 and close the clamp and cutter blades to cut and clamp the thread. During the closing of the mechanism C the stud 54 Will be raised by engagement of the mea-ns S2 with the lug 51 while the stud is still behind the rod 63. During the backward motion of the lay immediately following the cutting operationA the transfer arm will move toward its normal position and the operator 16 will move rearwardly so that the spring 29 can move the carriage 39 forwardly along the rail 37. During this forward movement the stud 54 will strike the rear end of the rod 63 but the latter being resiliently mounted will movel to the right, Fig. 3, in the bearings 61 land 62 without disturbing the setting of the movable cutter blade 43. Because of the fact that the stud 54 and the rod 63 move along divergent paths continued forward motion of the carriage 39 will result inultimate separation of the two parts 54 and 63 as the latter moves upwardly.

Another feature of the invention grows out of the fact that the axis of the member 63L and the path traversed by the stud 54 are oblique to eachother and lie in vertical planes which. are at an angle to each other. As a result of thisV relation each time the mechanism C is movedrrearwardly the stud 54 moveslaterally with respect to member 63, to the right thereof asl viewed in Fig. 2,v while in contact with the member 63 and therefore tendsto turn the latter so that new surfaces thereof are presented to the stud 54 toreduce wear on the member 63. This tendency to turn the rod 63 occurs when the spring 64 is expanded so, that the spring exerts a minimum force tending to resist rotation of the member. The diagonal path tranversed by stud 54 grows out of the fact that the raill 37 is obliquely disposed with respect to the lay as shown in Fig. 2, but this is not essential so long as the path is oblique withrespect to the axis of the member. 63. The path and axis are intersecting vertical planes both of which are transverse of the lay.

From the foregoing, it will 4be seen that the invention.

ber 63 the latter issubjected toaforce tending toturnit;

at each rearward motion of the mechanism C. While the spring 64 has been shown it is within the spirit of the invention to rely upon gravity to move the rod member 63, designated herein as the other part of the two cooperating parts which open the mechanism C to its normal rear position. When a spring is used it will be weak and of just sufficient strength to insure return of the member 63 to its rearmost position. The nuts on the forward end of the rod or member 63 permit an adjustment to determine the amount by which the stud 64 will be depressed when the mechanism C moves rearwardly. During the forward return of the mechanism C the parts 54 and 63 move along paths which diverge from each other so that these parts ultimately separate without opening the cutter and clamp mechanism.

Having now particularly described and ascertained the nature of the invention and in what manner the same is to be performed, what is claimed is:

1. In a thread cutter for a weft replenishing loom provided with a backwardly and forwardly reciprocating lay, thread cutter and clamping mechanism including relatively movable blades normally in closed position and forward of the lay, positioning means which incident to a weft replenishing operation of the loom moves said blades rearwardly and thereafter moves them forwardly along a given path, opening means for said mechanism including two cooperating parts one of which is on one of said blades and the other `of which is an elongated slidably mounted member freely rotatable about the longitudinal axis thereof, resilient means normally maintaining said member in stationary rearward position but enabling said member to slide forwardly from said rearward position along a divergent path at an angle to said given path, said other part remaining at said normal rearward position thereof when said blades move rearwardly to engage said one part and cause the latter to move from its normal position to effect relative movement of said blades to the open thread receiving position thereof, means on the lay operative to close the blades and return said one part to the normal position thereof, and said positioning means effective when moving said blades forwardly to cause engagement of said parts and cause movement of said other part by said one part along said divergent path thereof against the action of said resilient means to effect separation of said parts without moving said blades to open position, after which said other part is returned to the normal rearward position thereof by said resilient means.

2. The thread cutter mechanism set forth in claim 1 wherein said given path is in a vertical plane oblique to the lay and said divergent path is in a vertical plane substantially at right angles to the lay and said one part when moving rearwardly along said given path in engagement with said other part tends to turn the latter around the axis thereof.

3. The thread cutter mechanism set forth in claim l wherein said blades and said one part move along a rail oblique with respect to the lay and a stand mounts said member for sliding movement along a path which extends upwardly and forwardly from the lay.

4. The thread cutter set forth in claim 3 wherein the stand has front and back bearings in which the member slides and the resilient means is a spring between the bearings and around the member urging the latter to the said normal rearward position thereof.

5. The thread cutter set forth in claim 4 wherein an adjusting means on said member positioned for engagement with said front bearing affords means for varying the amount of movement imparted to said one part by said member when the blades are moved rearwardly by said positioning means.

6. In thread cutter mechanism for a weft replenishing loom provided with a backwardly and forwardly reciprocating lay, a pair of cutter blades normally in closed position and forward of the lay, positioning means acting incident to a weft replenishing operation of the loom to move said blades rearwardly and thereafter move them forwardly along a given path, opening means including two cooperating parts one of which is on one of said blades and the other of which is an elongated member, means mounting said member for sliding movement along and rotation about an axis inclined downwardly and toward the lay, said member normally being in a stationary rearward position but capable of sliding forwardly on said mounting means from said rearward position thereof, said mounting means causing the axis of said member to be at an angle to said given path, said other part when said blades move rearwardly remaining at said normal position thereof to engage said one part and move the latter from its normal position to effect opening of said blades to thread receiving position, means on the lay operative when the lay moves forwardly to close the blades and return said one part to the normal position thereof, and said positioning means effective when moving said blades forwardly to cause engagement of said parts and cause movement of said other part by said one part along said axis to eiect separation of said parts, after which said other part returns to the normal rearward position thereof.

7. In a weft replenishing loom provided with a lay, threaded cutter and clamping mechanism normally in forward closed position but moving rearwardly toward the lay incident to a weft replenishing operation of the loom, two cooperating parts effective when the mechanism moves rearwardly to engage each other and act due to movement of the mechanism to cause the latter to move to open thread receiving position, one of said parts being on and moving with the mechanism, means guiding the mechanism causing said one part to move along a given path toward the lay, and the other part including a member rotatable about an axis, said path and said axis lying respectively in vertical planes at an angle to each other and both planes being transverse of the lay, said one part when moving rearwardly while engaging said other part moving laterally with respect to said other part and tending to turn said other part to enable the latter to present different parts thereof for engagement with said one part.

8. A weft replenishing loom set forth in claim 7 wherein said member is urged to the normal rearward position thereof by a spring which exerts a minimum force on the member when the latter is in the normal position thereof and thereby exerts a minimum force tending to resist turning of the member. ,l

9. A weft replenishing loom set forth in claim 7 wherein said member is slidable in a fixed stand having front and back bearings and a compression spring between the bearings surrounding the member urges the latter to the rearward position thereof and is in the most expanded condition thereof to offer minimum resistance to turning of the member when the latter is in said rearward position thereof.

10. A weft replenishing loom set forth in claim 7 wherein the member is slidable in a stand having bearings for the member so disposed that the latter tends due to the weight thereof to move to the normal rearward position thereof.

11. A weft replenishing loom set forth in claim 7 wherein said path along which said one part moves is oblique with respect to the lay and the axis of the member is in a vertical plane which is substantially at right angles to the lay.

References Cited in the le of this patent UNITED STATES PATENTS 2,711,193 Consoletti June 2l, 1955 

